System of control for electric elevators.



F. C FURLOW.

SYSTEM 0? CONTROL FOR ELECTRIG'ELEVATORS.

' APPLICATION FILED NOV. 5,19l5.

' 1,268, 1 1 1 Patented June 4, 1918.

2 SHEETS-SHEET 1..

. ATTORNEY F. G. FURLOW.

SYSTEM OF CONTROL FOR ELECTRIC ELEVATORS.

APLICATlON FILED NOV. 5 I915. Patented June 4. 1918.

2 SHEETS-SHEET 2.

l/VVENTOR J ,4 TTOR/VE Y 1 control for. electrically operated elevators.

UNITED STATES PATENT OFFICE. I

FLOYD c. mow, or-mom'cnam, NEW JERSEY, assrenon 'ro o'rrs nnnva'ron. corp 'rmi'rlor .masm' orry, .masEY, a conrom'non or mrw mnsmr.

srsrmr or coirrnor. 103 name nnnvarons To whom; it may comm:

Be it known that I, FLOYD CaFURIDW, a

citizen. of the. United States, residin in ing is a. specification.

My invention relates to elevators, and more particularly ,to an improved-system of The invention more essentially consists in the provision ofin'eans, automatically to control ,an-elevator car in stopping to effeet ancxact landin the elements involved in accomplishing this result being 0 erable inde .ijjdently of the car speed and load, andeing in the form of auxiliary apparatus, operable independently of the mam motive and controlling means. Y

As is well known, considerable skill and accuracy is necessitated on the part of an elevator operator, in order to stop the elevator car exactly at a floor landing. This is so particularly on account 'of the tendency of the elevator carto coast or overrun alanding, even after the motive power is cutofiand the'brake applied. Thus for -varying'car loads and speeds it becomes most difigcult to efiect an exact car landing, it being the case in many instances for the elevator car to either overrun or underrun 'the landing, in" which event the operator then resorts to what is commonly termed an inching operation to brin the car exactly level with the; landing. his operation is objectionable for the reasons that it. disrupts the car schedule and is waste ful of power. Thu'sit is the aim of the. present invention to overcome the above objectionable features, .in a most practical and simple manner as illustrated'in the acwith the present invention; Fig. 2 is a companying drawings, in which 1 illustrates 1n general arrangement 118 1 111913 essential elements of a car switch controlled electrical elevator system, in accordance somewhat enlarged elevational view of a certain portion of Fig. 1, taken on the line a -a in direction of the arrows b-b, certain parts being broken away; Fig. 3 is a side'vieW of Fig.2 with'certain-parts in section.

The apparatus consists of an elevator car -to the worm wheel.

may be of either a direct or alternating cur-. rent type, the latter type being illustrated herein, it receiving current from an alternatin current source of supply, designated D, D D. A brake ulley P is rotatable with the main motor aft 1.

Patented June 4,1918.

The direction of rotation of the M is controlled by means ofelectro-inagnetic reversing switches R, R, whose operating windings are controlled from the elevator car by a usual car switch S.

The parts thus far described form the more essential elements of a typical elevator system with well known functions, and are thus described only in general.

Coming now to the elements which form more particularlythe subject matter of the present invention, they: willfbefdescribed in detail; A reversible auxiliary motorX is adapted to rotate a worm 2, in mesh with a'worm Wheel 3. The worm wheel 3 is carried loosely on the'main motor shaft 1. A brake apparatus B is rotatable bodily with the worm wheel 3, and about the brake pulley P. Arms 4 connect the brake apparatus The brake apparatus may be of any well ldIOWIl type in which the brake shoes 5 are released electrically, as by means of an electromagnet 6, and applied mechanically, as by means of the usual rake springs 7. I

The auxi any motor as 'before stated is reversible, the circuits controllin the same being controlled by a pair 0 electrical switches 8 and 9 pivotally mounted on the elevator can j These switches in turn are controlled independently bymeans of cams 10 and 11, fixed in the elevator hatchway at the floor' landing.- Although only one floor landin and one set of cams thereat, is illustrate herein, it will be understood that there may bean number of floors,

with a duplicate set 0 cams at each floor. Thus in order'to avoid unnecessary'duph-- cation and in view of the fact that a dupliiary motor in a manner to operate the car upwardly.

Auxiliary'back contacts 12, 12 on the reversing switches act in conjunction with the switches 8 and 9 to control the auxiliary motor circuits.

The variouselementsthrough a complete cycle of operation will now be described.

With the car switch S in center position,

the car and its operating-elements are at .rest, with the brake shoes applied to the brake pulley P by the springs Assume now it is desired to cause the elevator car to descend, say from an upper floor, down to the floor at which the car is shown.

For the operation we will assume the car switch is 'operated toward the left hand, bringing the segment 14 into electrical engagement with the fixed contact 15. A circuit is now completed for I the operating winding of the reversing switch R, causing the same to close, and thereby direct current to .the motor M and brake magnet 6. The brake magnet will now operate to a .release the brake shoesfrom the brake pulley P, andthe motor will now rotate in a direction to cause the elevator car to descend. As the carlapproaches the desired landing it is stop ed, by the operator centering the car switc S, thus disconnecting the motor and brake from the source of power supply.

The brakeshoes will now be applied to the pulley P, bringing the car to rest Assume now for example,- that thedescehding car I is heavily loaded, and that after the car I toactuate t switch is centered, the car tends to coast past or overrun the landing. Now in order to meet thiscontingency, the auxiliary motorfis brought into operation automatically the roller 9 associated with the switch "9 into engagement with the cam 11, thus closing the switch, This switch 9 now being; closed directs current to the auxiliary motor X and the phases onleads being traced] byway of wires D and 16 to back contacts 12, of reversing switch R, wire 17 to back contacts 12 of reversing switch R, wire 18, contacts 19, and thence to the terminal by way of wire 20; wire .21 is a common return e elevator car to eflect an exact landing, the operation. being as follows. The car having overrun the landing, brings} ing or descending.

'1 through the connections comprising the worm 2, worm wheel 3, and the brake apparatus B, whose shoesare now applied to the brake pulley P. The brake apparatus B now rotating bodily with the brake shoes applied to the pulley, in this instance now serves as a form of clutch mechanism or connector between the auxiliary motor X and the elevator car. In this manner, the shaft 1 is caused to rotate and through the worm and gear connection G, efi'ects an upward movement of the elevator car at an approximately slow speed. Now.the 1nstant the car becomes. exactly level with the floor landing,the roller 9 rides off the cam 11, thus permitting the switch 9 to open, and in this manner cause the auxiliary motor to be stopped. It will bepointed out, that the worm 2 and. worm wheel 3 are in practice, designed so as to 01m practically a lock between the auxiliary motor and rotatable brake apparatus, so that with all the parts at rest, the brake apparatus will, in view of the lock formed by the worm 2 and worm wheel 3," act positively to hold the I elevator car at rest.

Now in case the operator centers the car switch, to cause the descending car to stop some distance above the landing, the roller 8 will in this event, engage the cam 10 to close the switch 8. The switch .8 beingclosed directs current to the auxiliary motor to effect an operation thereof in a reverse direction to that just. described, thereby causing the elevator car to descend at an approximately slow speed. The instant the supply of current to the auxiliary motor is cut off, by reason of the roller 8 riding off the cam 10. In this manner the elevator car is stopped exactly level with the floor landmg. I

In operating the elevator car in an' ascend ing direction of travel, the parts operate in car comes level with thefloor landing, the

substantially the same manner as heretofore described in connection with the descending direction of travel. In'this instance, however, the' reversing switch Bfcloses, and directs current to the main motor M tocause it to rotate in a reverse direction to that just described, thereby causmg the car to.

ascend. p I However, the auxiliary apparatus for auto- "matically controlling the elevator car to effect an exact landingoperates as just de scribed, in the event of the car overrunning or underrunmng a landing, either in ascend It will be noted that sinc'egthe circuits for" the auxiliary motor incIu'de -the'back contacts on the reversing switches R) mice, a simultaneous operation between the main and auxiliary motors is efiectively prevented; or, in other words, the auxiliary motor ,is operable automatically only in the event of the car switch being centered, with the elevator car bearing suchrelation to the landi as to bring the switches 8 and 9 thereon 1nto engagement with a respective cam 10 or 11. In an application, Serial Number 59,736,

filed November 5, 1915 I have described and shown a hydraulic elevator, with electric means to control the same, to level thecar with a landing; but I 'do not claim in the application Serial Number 59,738, a hydraulic elevator.

- It will be understood that the invention is equally applicableto a direct current elevator system as well as to an alternating current system as herein shown, and to an automatic push button controlled elevator, as

well as a car; switch controlled elevator.

()ne skilled in the art may make obvious changes in the details and arrangement of I parts without departing from the spiritand scribed.

. 'What I claim scope of my invention, and I wish therefore not to be limited to the precise arrangement and details as are herein illustratedand deas new and desire to secure by Letters Patent of the United States is 1. In an electric elevator, the combination of the car, an electric hoisting motor,

' v' and electric means to control the motor, au-

tomatically controllable by the movement of 9 the car, to cause the motor to operate to bring the car to a level with a deslred landv v the said landing.

ingwhether the car over-runs or under-runs 2. In an electric elevator, the combination 7 of the car, an electric hoisting motormechanism,-- av controller therefor, comprising switches, on the car, in the circuit of the motor l'necha'nism, and cams on the hatchway ftoiclose the switch on the car, as and when the: car approaches a desired landing, and

release the switch to open position, upon the car becoming level' with the said landing. 3. In an electric elevator, the combination of the car, an electric main hoisting 'motor and an auxiliary electric hoisting motor to operate. the car, an automatically operable electric means, controllable by the movement of the car, and operable by the move ment of the car whether the car over-runs 'or under-runs a desired' landing, automatically to control'the operation of the auxlliary motor to level the car with the landing, 4. In an elevator, the combination of-thc car, an electric hoisting motor mechanism,

electric means to control the hoisting motor mechanism, automatically operable f by the movement of the car, at a landing to cause the hoisting motor mechanism to operatetto maintain in effect the car level with the, landing, in loading and unloading.

5. In an elevator, thecombination of the car, an electric hoisting motor mechanism, an operating circuit for the motor mecha- ,nism, electric means, comprising switches on the car, operable to close the circuit, and cams on the hatchway, to engage the switches, to close them, operable by the ,movement of the car, at the landing, to close the'switches or release them to open position, to cause the motor mechanism to maintain ineffect the car level with the landing, in loading and unloading.

6 In an elevator, the combination of the car, a hoisting motor mechanism, an electric operating circuit for the hoisting motor mechanism, switches in the circuit, carried on the car, cams on the hatchway, at a floor landing, to engage and close the switches by the movement of the car, to close the circuit to the hoisting mechanism, and to release the switches to open the said circuit, the camsand switches being positioned relatively to each-other close enough togetherso that, upon the movement. of the car from a position of rest level with the landing in loading or unloading, the cams will thereupon- .engage the'switches and close them, to

8. In an elevator, thecombiuation of amain electric hoisting motor, a controlling mechanism therefor, an auxiliary electric, hoisting motor, an operating circuit therefor, a controlling mechanism for the auxiliary motorincluding a switch and means con;

trollable bythe controlling mechanism for the. main motor, to cause the operating "circuitfor'the auxiliary motor to close, automaticallyto level the,car with a-landing whether the car over-runs or under-runs the landing when the main motor is not in operation in hoisting. v y

9. In an elevator, the combination of an electric hoisting motor mechanism, ,,com prising main andauldliary motors, si1pply and reversing switches, the latter carrying back contacts, in the supply circuit for, the auxiliary motor, the back contacts being closed whenthe carswitch is in an open position, switchesyin the circuit for the auxiliary motor, cams to engage and circuits therefor, a car, and a car switchclose the latter switches and subseduently to release themto open position, by the movemovement ;of the car as it approaches a ment of'the car. a 10. Inan electric elevator, the combination of the car,' an electric hoisting motormechanism, controlling switchesfor the motor mechanism, a cam to-closeone of the switches by the movement of the car as and when it approaches a landing, tohave the motor mechanism continue in hoisting 0peratlon in order to move the car to the landing, and substantially when the car is' level with the landing, to release the switch,

to open position, to allow the motor mechanism to cease its hoisting operation, and an additional" cam to close another one of the switches by the movement of the cai in" case the car over-run'the landing, and'eflect a movementof the car in a reversedireotion, to bring the car back' to the landing overfor the motor mechanism, a cam to close one of the}, additional controlling switches by landingiand thereby cause the motor mechanism, to continue its hoisting, operation to move the car toward the landing, and when.

the car is level with the landing, to release the switch to an open posltion and allow the 1.0a! to stop, an. additional cam operable by the car, if and when the car 'in its movement shall coast past the landing, to closeone of the said switches, and efiect a .move ment of the car in a reverse direction,,and bring the car back to the landing over-run and thereupon release the switch to stop the car at the landing, and means to prevent the said additional controlling switches ,from functioning while the car is under the control of the switch first named above.

In testimony whereof, I have signed my name to this specification in the presence of:

two subscribing witnesses.

' FLOYD o. mmLow.

Witnesses:

Jnssn H. VAN Anrnm, Tt M. 

